Oval centerpost and cooperating filter cartridge

ABSTRACT

A fluid filter centerpost assembly in combination with a fluid filter cartridge for creating a “no filter-no run” design according to one embodiment of the present invention comprises an oval-shaped design for the centerpost assembly and an oval-shaped design for a seal that is positioned between the centerpost assembly and the fluid filter cartridge. The centerpost assembly includes a main body having an oval shape in lateral cross section in unitary construction with a radial flange and interior shelf. The interior shelf defines a flow opening and a movable valve ball is positioned on the interior shelf and is able to move in the direction of the flow opening due to incoming fluid pressure. The fluid filter cartridge includes a closed endcap with a blocking pin such that when the fluid filter cartridge is installed, the blocking pin is positioned to prevent the valve ball from closing off the flow opening.

This is a reissue application of U.S. application Ser. No. 10/822,433now U.S. Pat. No. 6,884,349.

BACKGROUND OF THE INVENTION

The present invention relates in general to fluid filtration devicesthat are constructed and arranged to filter an incoming fluid prior toutilization of that fluid downstream from the filtration site. Morespecifically, the present invention relates to a fuel filter thatincludes a centerpost assembly and a replaceable filter cartridge thatslides onto the centerpost assembly. One focus of the present inventionis the concept of preventing fuel delivery to the engine if a “proper”filter cartridge is not installed on the centerpost assembly. In thecontext of the present invention, the term “proper” is used to describea filter cartridge that is approved for use by the original equipmentmanufacturer. It is important that the replacement filter cartridgemaintain design compatibility so that it fits properly and is properlysealed around the centerpost assembly.

In a more generic sense, the concept of “no filter-no run” means that ifa filter cartridge is not installed, there is no appreciable flow offuel to the engine. While the present invention provides this type ofstructure by its design of a “proper” filter cartridge, the specifics ofthe centerpost assembly and filter cartridge construction are important.One beneficial feature of the present invention is that its selectedconstruction for this flow-control feature is not restrictive to theflow of fuel. If the selected construction for the flow-control featurewere to introduce too much restriction, this could cause fuel systemproblems or inefficiencies.

Any prior art filter structures that try to address the desire for a “nofilter-no run” design are considered to have various disadvantages. Forexample, the resulting structures are typically either too complicated,too hard to service, too costly, or have a flow-control valveconstruction that is too restrictive to the fuel flow. Another designdisadvantage of earlier designs is that typically whatever mechanism isutilized to open a closed valve, there is a mechanical interaction whichsimply introduces additional design complexity and the potential forfailure. The present invention provides a novel and unobvious structureto create a “no filter-no run” fuel filter structure that overcomes manyof the disadvantages with earlier designs.

SUMMARY OF THE INVENTION

A fluid filter centerpost assembly in combination with a fluid filtercartridge for creating a “no filter-no run” design according to oneembodiment of the present invention comprises an oval-shaped design forthe centerpost assembly and an oval-shaped design for a seal that ispositioned between the centerpost assembly and the fluid filtercartridge. The centerpost assembly includes a main body having an ovalshape in lateral cross section in unitary construction with a radialflange and interior shelf. The interior shelf defines a flow opening anda movable valve ball is positioned on the interior shelf and able tomove in the direction of the flow opening due to incoming fluidpressure. The fluid filter cartridge includes a closed endcap with ablocking pin such that when the fluid filter cartridge is installed, theblocking pin is positioned to prevent the valve ball from closing offthe flow opening.

One object of the present invention is to provide an improved fluidfilter centerpost assembly and fluid filter cartridge combination.

Related objects and advantages of the present invention will be apparentfrom the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view, in full section, of a fluid filtercenterpost assembly in combination with a fluid filter cartridgeaccording to a typical embodiment of the present invention.

FIG. 2 is a front elevational view, in full section, of the FIG. 1centerpost assembly.

FIG. 3 is a top plan view of the FIG. 2 centerpost assembly.

FIG. 4 is a front elevational view, in full section, of the FIG. 1 fluidfilter cartridge.

FIG. 5 is a top plan view of the FIG. 4 fluid filter cartridge.

FIG. 6 is a bottom plan view of the FIG. 4 fluid filter cartridge withan oval seal installed.

FIG. 7 is a front elevational view, in full section, of the sealillustrated in FIG. 4.

FIG. 8 is a top plan view of the FIG. 7 seal.

FIG. 9 is a bottom plan view of an open endcap comprising a portion ofthe FIG. 4 fluid filter cartridge.

FIG. 10 is a top plan view of an interior shelf portion of the FIG. 2centerpost assembly.

FIG. 11 is a front elevational view, in full section, of a fluid filtercenterpost assembly in combination with a fluid filter cartridgeaccording to another embodiment of the present invention.

FIG. 12 is a front elevational view, in full section, of the FIG. 11centerpost assembly.

FIG. 13 is a top plan view of the FIG. 12 centerpost assembly.

FIG. 14 is a front elevational view, in full section, of the FIG. 11fluid filter cartridge.

FIG. 15 is a top plan view of the FIG. 14 fluid filter cartridge.

FIG. 16 is a bottom plan view of the FIG. 14 fluid filter cartridgeincluding an oval seal.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended, such alterations and furthermodifications in the illustrated device, and such further applicationsof the principles of the invention as illustrated therein beingcontemplated as would normally occur to one skilled in the art to whichthe invention relates.

Referring to FIG. 1, portions of a fuel filter that depict the structureof the present invention are diagrammatically illustrated. Theseportions include, in combination, a centerpost assembly 20 and a fluidfilter cartridge 21. The centerpost assembly 20 is further illustratedin FIGS. 2 and 3. The fluid filter cartridge 21 is further illustratedin FIGS. 4, 5, and 6. The centerpost assembly 20 includes a hollow mainbody 22 that is a unitary, molded plastic structure with an integralradial flange 23 adjacent the lower end and an integral interior shelf24 that is inclined at an approximate 30 degree angle relative to theaxial centerline 25 of main body 22. Assembled into the upper end 26 ofmain body 22 is a cap 27 that includes a centered clearance opening 28.The centerpost assembly 20 is completed by the addition of valve ball 36positioned on inclined interior shelf 24.

The sidewall 31 of main body 22 defines an inlet flow opening 32 that ispositioned just above the location where the interior shelf 24 isunitarily joined (i.e., molded) to the inside surface 33 of the mainbody 22. The interior shelf 24 defines a central flow opening 34 and arecessed track 35. The geometric center of flow opening 34 is concentricwith the cylindrical main body 22 and coaxial with centerline 25. Thevalve ball 36 rides in the recessed track 35 and is movable across theupper surface of interior shelf 24 in response to incoming fuel flow. Aswould be understood, due to the inclined nature of shelf 24, valve ball36 will naturally position itself between the interior shelf 24 and theinside surface of main body 22. The incoming fuel flow and the pressurefrom that flow is able to move the valve ball 36 toward the center offlow opening 34. The valve ball 36 is a molded plastic sphere and isdesigned to be light in weight such that virtually any fuel flowpressure is capable of moving the valve ball in the direction of flowopening 34. Further, the diameter selected for valve ball 36 issufficiently large that it has very little distance to move to be in aposition to actually close off flow opening 34. As indicated, thisdiameter size allows the valve ball to rest against inside surface 33 atthe edge of flow opening 32 on one side and be adjacent flow opening 34on the opposite side. If the valve ball 36 is actually allowed to moveto the center of flow opening 34, the valve ball 36 is constructed andarranged to close off flow opening 34 such that fuel is unable to reachany downstream location for fuel utilization. What prevents the valveball from closing off flow opening 34 is the presence of pin 37 which isan integral part of closed endcap 38. Pin 37 may alternatively beassembled into closed endcap 38 but, in either configuration, it isimportant that pin 37 extend coaxially with centerline 25 and extend inclose enough proximity to flow opening 34, based upon the overalloutside diameter of valve ball 36, so as to be able to prevent movementof the valve ball to a point that it could actually close off flowopening 34. It is actually the lower tip 42 of pin 37 that is positionedabove but still in close proximity to flow opening 34. As such, evenrelatively slight movement of valve ball 36 in the direction of flowopening 34 results in abutment of the outer surface of valve ball 36against pin 37, thereby stopping any further movement of valve ball 36.Pin 37 prevents the valve ball 36 from closing off flow opening 34 andthus this arrangement, as illustrated and described, means that as alongas there is a proper fluid filter cartridge installed with pin 37present, fuel will be permitted to flow to a downstream utilizationsite. However, without fluid filter cartridge 21 being installed ontocenterpost assembly 20, there is nothing to prevent the closing off offlow opening 34 by valve ball 36. As described, once there is anincoming flow of fuel, the pressure of that flow readily moves valveball 36 up the inclined shelf in the direction of flow opening 34,allowing the ball to seat and thereby close off flow opening 34. Withflow opening 34 closed by valve ball 36, there is no path for the fuelto reach any downstream location.

With reference to FIGS. 4, 5, and 6, filter cartridge 21 includes afiltering media 44, centertube 45, the closed endcap 38, an open endcap46, and an elastomeric seal 47 that is preassembled onto open endcap 36.The filtering media 44 and centertube 45 are each cylindrical andpreassembled together such that the centertube 45 provides structuralintegrity and support to prevent filtering media collapse. The openendcap 46 is bonded to the lower end of the filtering media 44 andcentertube 45 assembly. The circular, closed endcap 38 is bonded to theupper end of the filtering media 44 and centertube 45 assembly. Pin 37is centered in endcap 38 such that all of these assembled components areconcentric and coaxial. The longitudinal axis 48 of pin 37 is coaxialwith axial centerline 25 and with the center of flow hole 34.

While the filtering media 44, centertube 45, and endcap 38 are circularor cylindrical in overall shape, it is important to note thatelastomeric seal 47 is oval in shape, including an oval interior opening47a. This in turn results in the open endcap 46 having a circularoutside diameter (outer edge 48) and an oval or elliptical opening 49centered on the axial centerline 25. The point of intersection of themajor and minor axes of the oval shape coincides with axial centerline25. The details of elastomeric seal 47 are illustrated in FIGS. 7 and 8,including its oval shape. The oval shape of opening 49 and its centeredposition in endcap 46 are illustrated in FIG. 9.

With continued reference to FIGS. 2 and 3, the details of centerpostassembly 20 are illustrated. As will be seen from the FIG. 3illustration, the centerpost assembly 20 and in particular the main body22 has an oval shape in lateral cross section. As has been noted, theradial flange 23 also has an oval shape, as does closing cap 27 andinterior shelf 24. Closing cap 27 and its matching oval shape aredesigned to fit into the oval upper end 26. Circular opening 28 in cap27 is coaxially centered and is axially aligned with pin 37 and withflow hole 34. The assembly of cap 27 into end 26 can be by means of aninterference press fit or by the use of a suitable adhesive or by a spinweld.

As illustrated in FIG. 1, as fluid filter cartridge 21 slides down ontocenterpost assembly 20, oval seal 47 slides down oval main body 22 untilthere is abutment of seal 47 against the upper surface of radial flange23. The oval opening 47a is sized and shaped to generally match the sizeand shape of body 22, but with moderate compression of inner rib 47b. Itshould be understood that support of oval seal 47 by radial flange 23 isfacilitated and made more efficient by creating radial flange 23 with acorresponding oval shape and with sufficient size to fully receive seal47. In order to establish a sealed interface around the oval main body22, it is necessary to design and fabricate seal 47 with a properlysized oval opening 47a that experiences some moderate compression for aleak-free radial seal against body 22. The preassembly of the seal 47onto open endcap 46 requires that the opening 49 have a correspondingoval shape. By applying a moderate force on filter cartridge 21 for itsabutment against radial flange 23 and then maintaining that moderateforce, an oval compression seal can also be established between fluidfilter cartridge 21 and radial flange 23.

While the cooperating and supporting structures have been described inthe context of FIGS. 1-9, an important focus of the present invention isthe desire to create a fuel filter wherein there is a no filtercartridge-no run arrangement. This means that unless there is a “proper”filter cartridge installed onto the centerpost assembly 20, it is notpossible to have fuel delivered to any downstream location ofutilization. While a few drops of fuel might flow through, the point tobe recognized is that “no run” means insufficient fuel to perform anytypical or normal engine functions. Critical to achieving this no filtercartridge-no run capability is the design of the inclined interior shelf24, the use of valve ball 36, and the presence of pin 37. Importantly,this interior shelf 24 has an oval shape, as illustrated by the top planview of FIG. 10.

Referring to FIGS. 1 and 10, it will be seen, as described, that mainbody 22 has an oval or elliptical shape as does radial flange 23. Theinterior spaced defined by main body 22 is also oval or elliptical inshape and is closed off completely by shelf 24. The only opening orpassageway for the flow of fuel is by way of flow opening 34. Track 35is shaped as a narrow channel that extends from flow opening 34 to theinside surface 33 of main body 22. A lower shelf portion 53 providesadded material thickness for incorporating track 35 without it breakingthrough such that track 35 would create another flow path. Closing offtrack 35 ensures that the only flow path for fuel is through flowopening 34. Notwithstanding the various shapes, openings, walls andcurvatures, all of main body 22, including interior shelf 24 and radialflange 23, can be molded as a unitary component. This includes track 35and flow opening 24, as illustrated and described.

Referring now to FIG. 1, another embodiment of the present invention isillustrated. The illustrated assembly includes a centerpost assembly 60,fluid filter cartridge 61 and, as part of cartridge 61, an ovalelastomeric seal 62. Assembled to one end of filtering media 63 is aclosed endcap 64 and assembled to the opposite end of the filteringmedia is an open endcap 65 (see FIGS. 14-16). The centerpost assembly 60includes a main body 69, closing cap 70, and valve ball 71. Theconstruction and assembly of centerpost assembly 60 is intended to besubstantially the same as the construction and assembly of centerpostassembly 20. The only important difference is that centerpost assembly60 is shortened in an axial direction as compared to the overall lengthof centerpost assembly 20. Otherwise, centerpost assembly 60 andcenterpost assembly 20 are virtually the same, they are intended tofunction in the same way and have the same overall design philosophy,including the use of an oval radial flange 72, an inclined interiorshelf 73, also oval in shape, flow opening 74, flow opening 75, andtrack 76. The details of centerpost assembly 60 are illustrated in FIG.12. The oval shape of centerpost assembly 60, focusing primarily on mainbody 69 and the corresponding portions including flange 72 and closingcap 70, are illustrated in FIG. 13. As indicated, the overallconstruction and functioning of centerpost assembly 60 is the same ascenterpost assembly 20, including function, way, and result. This alsoincludes a virtually identical utilization and philosophy includingpositioning and movement for valve ball 71.

There are fuel filter applications wherein the centerpost or centerpostassembly must be shortened and this alternative design is represented bycenterpost assembly 60. However, the filter cartridge 61 must bemodified to accept and cooperate with the shorter centerpost assembly.The filter cartridge includes a centertube 80 and molded as a unitaryportion of centertube 80 is a dual-pin plug 81. Plug 81 is centeredaxially between opposite ends of filtering medial 63 and includes pin 82extending in the direction of open endcap 65 and oppositely thereto pin83 extending in the direction of closed endcap 64. Pins 82 and 83 arecoaxial with longitudinal centerline 84. This longitudinal centerline 84is coaxial with the longitudinal axes of filtering media 63, centertube80, and filter cartridge 61. Consistent with the design and constructionof centerpost assembly 20 and fluid filter cartridge 21, pins 82 and 83are centered on the circular center of opening 85 defined by closing cap70 and flow opening 75 defined by interior shelf 73.

The use of plug 81 allows pin 82 to function as described in connectionwith pin 37, without having to extend the increased length from closedendcap 64. Additionally, by using two pins oppositely arranged andcentered axially, it does not matter which end of filtering medial 63receives the closed endcap 64 and which end of the filtering mediareceives the open endcap 65 when creating the fluid filter cartridge 61.Either order of endcaps can be used and whichever end receives the openendcap, there will be a properly positioned and aligned pin for thecenterpost assembly 60 when the fluid filter cartridge slides down overthe oval centerpost assembly 60. Plug 81 is a molded plastic portion ofcentertube 80 and while either endcap can be used, the unitarycentertube 80 can be assembled in either direction into filtering media61.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiment has been shown and described and that allchanges and modifications that come within the spirit of the inventionare desired to be protected.

1. In combination: a fluid filter centerpost assembly comprising: a mainbody defining a first flow opening and an open interior and having anoval shape in lateral cross section; an oval-shaped radial flange; anoval-shaped interior shelf defining a second flow opening and beingpositioned on an incline in said open interior; a closing cap assembledinto said main body; and a movable valve ball positioned on saidinterior shelf; and a fluid filter cartridge received by said fluidfilter centerpost assembly comprising: a filtering media; a closedendcap assembled to one end of said filtering media, said closed endcapincluding a blocking pin, said blocking pin being constructed andarranged for limiting any movement of said movable valve ball in thedirection of said second flow opening; an open endcap assembled toanother end of said filtering media; and an oval-shaped seal received bysaid open endcap and being positioned around said main body and restingon said radial flange.
 2. The combination of claim 1 wherein said mainbody is a unitary, molded plastic structure.
 3. The combination of claim2 wherein said interior shelf defines a track for guiding any movementof said valve ball.
 4. In combination: a fluid filter centerpostassembly comprising: a main body defining a first flow opening and anopen interior and having an oval shape in lateral cross section; anoval-shaped radial flange; an oval-shaped interior shelf defining asecond flow opening and being positioned on an incline in said openinterior; a closing cap assembled into said main body; and a movablevalve ball positioned on said interior shelf; and a fluid filtercartridge received by said fluid filter centerpost assembly comprising:a filtering media; a first endcap assembled to one end of said filteringmedia; a second endcap assembled to another end of said filtering media;an oval-shaped seal received by said second endcap and being positionedaround said main body and resting on said radial flange; and blockingmeans for limiting any movement of said movable valve ball in thedirection of said second flow opening.
 5. The combination of claim 4wherein said main body is a unitary, molded plastic structure.
 6. Thecombination of claim 5 wherein said interior shelf defines a track forguiding any movement of said valve ball.
 7. The combination of claim 4wherein said blocking means includes a protrusion extending from saidfirst endcap in the direction of said second flow opening.
 8. Thecombination of claim 4 wherein said filtering media is shaped with ahollow interior and said fluid filter cartridge further includes acentertube positioned within said hollow interior.
 9. The combination ofclaim 8 wherein said blocking means includes a structural memberpositioned within said centertube and a protrusion extending from saidstructural member in the direction of said second flow opening.
 10. Incombination: a fluid filter centerpost assembly comprising: a main bodydefining a first flow opening and an open interior and having an ovalshape in lateral cross section; an oval-shaped radial flange; anoval-shaped interior shelf defining a second flow opening and beingpositioned on an incline in said open interior; a closing cap assembledinto said main body; and a movable valve ball positioned on saidinterior shelf; and a fluid filter cartridge received by said fluidfilter centerpost assembly comprising: a filtering media formed into ashape to define a hollow interior; a first endcap assembled to one endof said filtering media; a second endcap assembled to another end ofsaid filtering media; an oval-shaped seal received by said second endcapand being positioned around said main body and resting on said radialflange; and a support plug positioned in said hollow interior, saidsupport plug including a blocking pin extending in the direction of saidsecond flow opening for limiting any movement of said movable valve ballin the direction of said second flow opening.
 11. The combination ofclaim 10 wherein said main body is a unitary, molded plastic structure.12. The combination of claim 11 wherein said interior shelf defines atrack for guiding any movement of said valve ball.
 13. The combinationof claim 12 wherein said support plug includes an alternate blocking pinextending in a direction opposite to the direction of said blocking pin.14. The combination of claim 13 wherein said support plug is constructedand arranged to be assembled into said hollow interior in either of twoorientations wherein one orientation has said blocking pin extendingtoward said second flow opening and wherein the other orientation hassaid alternate blocking pin extending toward said second flow opening.15. The combination of claim 10 wherein said support plug includes analternate blocking pin extending in a direction opposite to thedirection of said blocking pin.
 16. The combination of claim 15 whereinsaid support plug is constructed and arranged to be assembled into saidhollow interior in either of two orientations wherein one orientationhas said blocking pin extending toward said second flow opening andwherein the other orientation has said alternate blocking pin extendingtoward said second flow opening.
 17. An apparatus comprising: a fuelfilter cartridge including: a filtering media; a hollow interior; afirst endcap coupled to one end of said filtering media; a support plugpositioned in said hollow interior; a blocking pin extending from saidsupport plug into said hollow interior in a direction toward said firstendcap; and a second endcap coupled to another end of said filteringmedia and a second blocking pin extending from said support plug intosaid hollow interior in a direction toward said second endcap.
 18. Theapparatus of claim 17 wherein the support plug is centered axiallybetween a first end of the filtering media and a second end of thefiltering media and occupies a portion of the hollow interior effectiveto accommodate a fluid flow though the hollow interior past the supportplug.
 19. The apparatus of claim 17 further comprising a seal receivedby one of said first endcap and said second endcap, said seal having anoval shaped aperture leading to said hollow interior.
 20. The apparatusof claim 17 further comprising a filter centerpost assembly; whereinsaid centerpost is received by said hollow interior.
 21. A systemcomprising: a fuel filter centerpost including an internal flow passageand a sidewall having an inlet flow opening leading to said flowpassage; an inclined shelf positioned within said flow passage andhaving flow opening defined therein; and a ball positioned adjacent saidinclined shelf and being moveable by a fluid flow from a position notobstructing said flow opening to a position obstructing said flowopening.
 22. The system of claim 21 wherein said centerpost has an ovalshape in lateral cross section.
 23. The system of claim 21 wherein saidball is positioned in a recessed track provided in said shelf.
 24. Thesystem of claim 21 further comprising a filter element including ablocking pin, said filter element being coupled with said centerpostsuch that said blocking pin prevents said ball from moving to saidposition obstructing said flow opening.